The president appealed this in a letter to Manmohan Singh.
According to the Presidential spokesman Farhatullah Babar, the letter was sent through Pakistan High Commission in New Delhi.
President Zardari thanked his Indian counterpart for hospitality during his visit.
The issue of Dr. Khalil Chishti was discussed during President Zardari’s meeting with PM Singh recently in India, the spokesman said.
The 80-year-old ailing Pakistani scientist Dr Mohammed Khalil Chishti, who was granted bail by Indian Supreme Court on Monday in a two-decade-old murder case, has been released from a prison in Ajmer.
The president, in the letter, wrote that by doing so, relations between both countries will be strengthened.